This invention relates to a hitherto unknown class of compounds that show strong activity in inducing differentiation and inhibiting undesirable proliferation of certain cells, including skin cells and cancer cells, as well as immunomodulating and anti-inflammatory effects, to pharmaceutical preparations containing these compounds, to dosage units of such preparations, and to their use in the treatment and/or prophylaxis of diseases characterised by abnormal cell differentiation and/or cell proliferation such as e.g. psoriasis and other disturbances of keratinisation, HIV-associated dermatoses, wound healing, cancer, including skin cancer, and of diseases of, or imbalance in, the immune system, such as host versus graft and graft versus host reaction and transplant rejection, and autoimmune diseases, such as discoid and systemic lupus erythematosus, diabetes mellitus and chronic dermatoses of autoimmune type, e.g. scieroderma and pemphigus vulgaris, and inflammatory diseases, such as rheumatoid arthritis, as well as a number of other disease states including hyperparathyroidism, particularly secondary hyperparathyroidism associated with renal failure, cognitive impairment or senile dementia (Alzheimer""s disease) and other neurodegenerative diseases, hypertension, acne, alopecia, skin atrophy, e.g. steroid induced skin atrophy, skin ageing, including photo-ageing, and to their use for promoting osteogenesis and treating/preventing osteoporosis and osteomalacia.
The compounds of the invention constitute a novel class of vitamin D analogues represented by the general formula I: 
in which formula X is hydrogen or hydroxy or protected hydroxy; R1 and R2 stand for hydrogen, methyl or ethyl, or, when taken together with the carbon atom bearing the group X, R1 and R2 can form a C3-C5 carbocyclic ring; Q is a C3-C6 hydrocarbylene, hydrocarbylene indicating the diradical obtained after removal of 2 hydrogen atoms from a straight or branched, saturated or unsaturated hydrocarbon, in which one of any CH2 groups may optionally be replaced by an oxygen atom or a carbonyl group, such that the carbon atom (C-22) directly bonded to C-20 is an sp2 or sp3 hybridised carbon atom, i.e. bonded to 2 or 3 other atoms; and in which another of the CH2 groups may be replaced by phenylene, and where Q may optionally be substituted with one or more hydroxy or C1-C4-alkoxy groups.
Examples of I include, illustratively but not limitingly, the horizontal entries in Table 1 (p. 12), where for convenience Q is considered to be a composite of segments Qa through Qf, with any blank spaces being understood as direct bond, such that Qa is directly bonded to C-20, and R1 is the same as R2 unless otherwise noted. Thus, segments within Q such as methylene, methene (in contiguous pairs, i.e. carbon atoms connected by double bonds), methyne (in contiguous pairs, i.e. carbon atoms connected by triple bonds), phenylene (illustrated by m-phenylene), alkylidene (illustrated by 1,1-propylidene), hydroxymethylene, alkoxymethylene (illustrated by ethoxymethylene), keto, and oxa may be combined to produce side chains that are in fact identical (apart from the 17,20-double bond) to those already known from a variety of active vitamin D analogues.
The compounds of the invention can comprise more than one diastereoisomeric form (e.g. E or Z configuration of the 17,20-double bond and also of any non-ring double bond present in the group Q; R and S configurations when a hydroxy group or an alkoxy group or a branching atom is present in Q). The invention covers all these diastereoisomers in pure form and also mixtures thereof. In addition, prodrugs of I in which one or more of the hydroxy groups are masked as groups that can be reconverted to hydroxy groups in vivo could also be envisaged.
The compounds I may be obtained in crystalline form either directly by concentration from an organic solvent or by crystallisation or recrystallisation from an organic solvent or mixture of said solvent and a co-solvent which may be organic or inorganic, such as water. The crystals may be isolated in essentially solvent-free form or as a solvate, such as a hydrate. The invention covers all crystalline modifications and forms and also mixtures thereof.
A number of vitamin D analogues have been described that show some degree of selectivity in favour of the cell differentiation inducing/cell proliferation inhibiting activity in vitro as compared with the effects on calcium metabolism in vivo (as measured in increased serum calcium concentration and/or increased urinary calcium excretion), which adversely limit the dosage that can safely be administered. One of the first of these to appear, calcipotriol (INN) or calcipotriene (USAN), has been developed on the basis of this selectivity and is now recognised world-wide as an effective and safe drug for the topical treatment of psoriasis.
A study with another analogue selected on this basis supports the concept that systemically administered vitamin D analogues may inhibit breast cancer cell proliferation in vivo at sub-toxic doses (Colston, K. W. et al., Biochem. Pharmacol. 44, 2273-2280 (1992)).
Promising immunosuppressive activities of vitamin D analogues have been reviewed (Binderup, L., Biochem. Pharmacol. 43, 1885-1892 (1992)). Thus, a series of 20-epi-vitamin D analogues has been identified as potent inhibitors of T-lymphocyte activation in vitro (Binderup, L. et al, Biochem. Pharmacol. 42, 1569-1575 (1991)). Two of these analogues, MC 1288 and KH 1060, systemically administered, have shown immunosuppressive activities in vivo in experimental animal models. Additive or synergistic effects were observed in combination with low-dose cyclosporin A. KH 1060, alone or in combination with cyclosporin A, has also been shown to prevent autoimmune destruction of transplanted islets in diabetic NOD mice (non-obese diabetic mice) (Bouillon, R. et al. In: Vitamin D, Proceedings of the Ninth Workshop on Vitamin D, Orlando, Fla., Walter de Gruyter, Berlin, 1994, pp 551-552). MC 1288 was able to prolong survival of cardiac and small bowel grafts in rats (Johnsson, C. et al. In: Vitamin D, Proceedings of the Ninth Workshop on Vitamin D, Orlando, Fla., Walter de Gruyter, Berlin, 1994, pp 549-550). However, in all these studies, the dosages of the analogues that produced significant immunosuppression also induced increases in serum calcium levels. There is therefore a continuing need for new analogues with high potency showing an acceptable combination of prolonged therapeutic activity and minimum toxic effects.
The present invention provides a hitherto undisclosed series of vitamin D analogues which is characterised by the presence of a double bond between C-17 and C-20.
21-Nor-17(20)-ene vitamin D analogues are described in EP 0 717 034, but the only previously described vitamin D analogues with a C-17,20 double bond and the C-21 methyl group preserved are those with a C-22,23 triple bond (WO 94/01398). The compounds of the present invention extend the range of side chain types to comprise a more comprehensive selection of side chains known from prior art vitamin D analogues.
These compounds have been discovered to possess exceptionally high immunosuppressive activities together with high tumour cell proliferation inhibiting activities.
The following standard abbreviations are used throughout this disclosure:
18C6=18-Crown-6
AIBN=2,2xe2x80x2-azobisisobutyronitrile
b.p.=boiling point
Bu=n-butyl
But=tert-butyl
DIBAH=diisobutylaluminium hydride
DMAP=4-dimethylaminopyridine
DMF=N,N-dimethylformamide
DMR=Dess-Martin-Reagent=1,1,1-triacetoxy-1,1-dihydro-1,2-benz-iodoxol-3(1H)-one
Et=ethyl
Ether=diethyl ether
Fg=functional group
LDA=lithium diisopropylamide
Lg=leaving group
Me=methyl
m.p.=melting point
PCC=pyridinium chlorochromate
PDC=pyridinium dichromate
Ph=phenyl
PPTS=pyridinium p-toluenesulfonate
Py=pyridine
r.o.s.=xe2x80x9crest of sequencexe2x80x9d
TBABr=tetra-n-butylammonium bromide
TBAF=tetra-n-butylammonium fluoride
TBAOH=tetra-n-butylammonium hydroxide
TBAHSO4=tetra-n-butylammonium hydrogensulfate
TBS=tert-butyldimethylsilyl
Tf=trifluromethansulfonyl
TFA=trifluoroacetic acid
THF=tetrahydrofuran
THP=tetrahydro-4H-pyran-2-yl
TMS=trimethylsilyl
Tol=toluene
Ts=4-toluenesulfonyl
Compounds of formula I, as illustrated in Table 1, may be prepared by the general methods of Schemes 1 and 3. In Scheme 1, the vitamin D nucleus building block aldehyde la, is converted to a key intermediate of type II (Scheme 2) via the intermediates 2, 3 or 4. 
Notes to Scheme 1
(a) HCN
(b) 1) POCl3/Pyxe2x86x92IIf; 2) DIBAHxe2x86x92IIa
(c) W. von Daehne et al., poster at X vit. D workshop, Strasbourg 1997; WO 98/24762
(d) NaOH, CH2Cl2, TBABrxe2x86x92IIa
(e) Cf. N. Ohmori et al., Tetr. Lett. 1986, 27, 71
(f) For IIb, IIc, IId and IIe: See Scheme 2
(g) See Scheme 3, Table 1, and xe2x80x9cMethods of Synthesis 1-7xe2x80x9d
(h) 1b (N=NCD): B. Fernandez et al., J.Org.Chem. 1992, 57, 3173 1b (Nxe2x95x90NE): K. Hansen et al., in: Vitamin D: Gene Regulation, Structure-Function Analysis and Clinical Application; Norman, A. W., Bouillon, R., Thomasset, M., Eds.; de Gruyter, Berlin, 1991, pp 161-162
(i) Fernandez et al., J.Org.Chem. 1992, 57, 3173
In Scheme 2 the method of preparation of each type of compound II, that is IIa, IIb, IIc, IId, and IIe from compound 2, 3 and 4 is outlined. In Table 2 and preparations 1 to 6, 10, 18, 31 and 34 the synthesis of some compounds of types IIa, IIb and IIc are described in more detail. 
Notes to Scheme 2
(a) See Table 2, Preparations 1-4, and 31.
(b) NaBH4/CeCl3 
(c) Lg=leaving groups, such as e.g. halide (Cl, Br, I), lower alkanoate, p-toluenesulfonate (tosylate), methanesulfonate (mesylate) or trifluoromethanesulfonate (triflate).
(d) The compounds IIc are obtained from IIb by standard procedures using suitable acid derivatives corresponding to the required Lg.
(e) 1) PhSxe2x88x92-K+, 2) H2O2, NaWO4 (M. J. Calverley, in: Trends in Medicinal Chemistry ""90; S. Sarel et al. Eds., Blackwell Scientific Publ., Oxford 1992, pp 299-306).
(f) B(SeMe)3, TFA, CH2Cl2, (WO 89/10351; M. J. Calverley, Tetr. Lett. 1987, 28, 1337).
In Scheme 3 the synthesis of compounds I from the key intermediates II (a-e) is outlined in a general manner. More detailed descriptions for the synthesis of the preferred compounds I, listed in Table 1, are given in the xe2x80x9cMethods of synthesis 1-7xe2x80x9d, and in further detail in the Preparations (Table 3) and Examples (Table 4). 
Compounds II are first reacted with side chain building blocks Fgxe2x80x94Zxe2x80x94W, to give the intermediates Jxe2x80x94Qpxe2x80x94Zxe2x80x94W. Fg is a reactive functional group, the kind of which is indicated in the Methods of synthesis 1-7; Z is a linking group, which together with Qp forms a side chain moiety which may either be identical to Q in compound I, or alternatively may be a moiety which can be converted to Q at any subsequent stage in the synthesis; Qp is a part of Q which may either be identical to Qa, or to Qa,Qb, or to Qa,Qb,Qc, depending on the particular method of synthesis, or Qp may similarly be converted to Qa, or to Qa,Qb, or to Qa,Qb,Qc later during the synthesis; W is either identical to the group CX(R1)(R2) in compound I, or may be similarly converted thereto later during the synthesis.
The remaining steps in the synthesis involve the below mentioned operations 1-4, in the following called xe2x80x9crest of sequencexe2x80x9d, abbreviated xe2x80x9cr.o.s.xe2x80x9d; these operations may be performed in any desired order, according to the synthetic demands of each particular Compound I to be prepared:
1 Optional conversion of the group Qpxe2x80x94Z to Q;
2 Optional conversion of the group W to C(R1)(R2)(X).
3 Optional conversion of the group NE/NCD to the group NZ by:
a Triplet-sensitised photoisomerisation of the vitamin D triene (5E to 5Z); or
b Desilylation, oxidation to the ketone and Horner coupling with the A-ring building block 5 of Scheme 3 (see e.g. WO 94/14766);
4 Conversion of the group NZ to the group M by removal of the vitamin D nucleus silyl protective groups.
Note to Table 1
The compounds may have either 17(20)E or 17(20)Z-configuration, both configurations are included. For compounds with a 22-OH or 22-OR3 substituent, both 22R and 22S configurations are included. For compounds with double bonds at C-22, C-23 or C-24, both the E and Z configurations are included.
Methods of Synthesis: 1-7
The methods described in the following are based on procedures described for the preparation of vitamin D analogues having a 17xcex2,20-single bond with either xe2x80x9c20-normalxe2x80x9d or xe2x80x9c20-epixe2x80x9d configuration instead of the 17,20-double bond of the compounds of the present invention.
Reference is given to this prior art, in which experimental details can be found.
The following definitions are used:
R3=C1-C5 alkyl; Y=Halogen. Other symbols and abbreviations have the above meanings.
Abstracts of the paper and posters, presented at the Tenth Workshop on Vitamin D, Strasbourg, Francexe2x80x94May 24-29, 1997, which are mentioned in this application, are published:
a) Bretting, C. et al., pp. 77-78;
b) Calverley, M. et al., pp. 30-31;
c) Hansen, K. et al., pp. 87-88;
d) von Daehne, W. et al., pp. 81-82
in Vitamin D: Chemistry, Biology and Clinical Applications of the Steroid Hormone (Editors Norman, A. W.; Bouillon, R.; Thomasset, M.), University of California, Riverside, 1997. 
The present compounds are intended for use in pharmaceutical compositions which are useful in the local or systemic treatment of human and veterinary disorders as described above.
The present compounds may be used in combination with other pharmaceuticals or treatment modalities. In the treatment of psoriasis the present compounds may be used in combination with e.g. steroids or with other treatments e.g. light- or UV-light-treatment or the combined PUVA-treatment. In the treatment of cancer the present compounds may be used in combination with other anti-cancer drugs or anti-cancer treatments, such as radiation treatment. In the prevention of graft rejection and graft versus host reaction, or in the treatment of auto-immune diseases, the present compounds may advantageously be used in combination with other immunosuppressive/immunoregulating drugs or treatments, e.g. with cyclosporin A.
The amount required of a compound of formula I (hereinafter referred to as the active ingredient) for therapeutic effect will, of course, vary both with the particular compound, the route of administration and the mammal under treatment. The compounds of the invention can be administered by the parenteral, intra-articular, enteral or topical routes. They are well absorbed when given enterally and this is the preferred route of administration in the treatment of systemic disorders. In the treatment of dermatological disorders like psoriasis or eye diseases topical or enteral forms are preferred.
While it is possible for an active ingredient to be administered alone as the raw chemical, it is preferable to present it as a pharmaceutical formulation. Conveniently, the active ingredient comprises from 0.1 ppm to 0.1% by weight of the formulation.
The formulations, both for veterinary and for human medical use, of the present invention thus comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredient(s). The carrier(s) must be xe2x80x9cacceptablexe2x80x9d in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
The formulations include e.g. those in a form suitable for oral, ophthalmic, rectal, parenteral (including subcutaneous, intramuscular and intravenous), transdermal, intra-articular and topical, nasal or buccal administration.
By the term xe2x80x9cdosage unitxe2x80x9d is meant a unitary, i.e. a single dose which is capable of being administered to a patient, and which may be readily handled and packed, remaining as a physically and chemically stable unit dose comprising either the active material as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers.
The formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the active ingredient into association with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing the active ingredient into association with a liquid carrier or a finely divided solid carrier or both, and then, if necessary, shaping the product into the desired formulation.
Formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules, sachets, tablets or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or non-aqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion. The active ingredient may also be administered in the form of a bolus, electuary or paste.
Formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and a carrier, or in the form of an enema.
Formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient. Transdermal formulations may be in the form of a plaster.
Formulations suitable for intra-articular or ophthalmic administration may be in the form of a sterile aqueous preparation of the active ingredient which may be in microcrystalline form, for example, in the form of an aqueous microcrystalline suspension. Liposomal formulations or biodegradable polymer systems may also be used to present the active ingredient for both intra-articular and ophthalmic administration.
Formulations suitable for topical or ophthalmic administration include liquid or semi-liquid preparations such as liniments, lotions, gels, applicants, oil-in-water or water-in-oil emulsions such as creams, ointments or pastes; or solutions or suspensions such as drops.
Formulations suitable for administration to the nose or buccal cavity include powder, self-propelling and spray formulations, such as aerosols and atomisers.
In addition to the aforementioned ingredients, the formulations of this invention may include one or more additional ingredients, such as diluents, binders, preservatives etc.
The compositions may further contain other therapeutically active, compounds usually applied in the treatment of the above mentioned pathological conditions, such as other immunosuppressants in the treatment of immunological diseases, or steroids in the treatment of dermatological diseases.
The present invention further concerns a method for treating patients suffering from one of the above pathological conditions, said method consisting of administering to a patient in need of treatment an effective amount of one or more compounds of formula I, alone or in combination with one or more other therapeutically active compounds usually applied in the treatment of said pathological conditions. The treatment with the present compounds and/or with further therapeutically active compounds may be simultaneous or with intervals.
In the systemic treatment daily doses of from 0.001-2 xcexcg per kilogram bodyweight, preferably from 0.002-0.3 xcexcg/kg of mammal bodyweight, for example 0.003-0.2 xcexcg/kg of a compound of formula I are administered, typically corresponding to a daily dose for an adult human of from 0.2 to 15 xcexcg. In the topical treatment of dermatological disorders, ointments, creams or lotions containing from 0.1-500 xcexcg/g, and preferably from 0.1-100 xcexcg/g, of a compound of formula I are administered. For topical use in ophthalmology ointments, drops or gels containing from 0.1-500 xcexcg/g, and preferably from 0.1-100 xcexcg/g, of a compound of formula I are administered. The oral compositions are formulated, preferably as tablets, capsules, or drops, containing from 0.05-50 xcexcg, preferably from 0.1-25 xcexcg, of a compound of formula I, per dosage unit.